A new indicator to estimate the efficiency of water and energy use in agro-industries

In the search of sustainable practices in agro-food industry, it is compulsory to carry out the adequate assessment and further comparison of their resource consumptions. In this respect, environmental evaluations in industry often just focus on water or energy consumption, avoiding integrated indicators to measure the overall efficiency and environmental sustainability of processes. In this paper, the authors being aware of this lack of integrated indicators in the agro-food sector, have presented a new indicator, the Water and Energy Use Indicator (WELD). It is operational, easy to interpret and communicate. Its main goal is to evaluate and further assess the global environmental performance of agro-industrial subsectors, and compare the overall efficiency of different industries. Additionally, the indicator allows to check if some proposed measures in an industry, apart from reducing their energy, water and resource consumption, leads to contribute or not to a higher level of environmental sustainability. Four complementary methodologies were adequately integrated into that single indicator: Water Footprint, Water Pinch, Life Cycle Assessment, and Exergy Analysis. Each methodology ranks the performance of a given industry with an index from 1 to 7 by comparing its operational parameters with the reference values within the corresponding agro-food subsector. The final indicator of the WEUI is then the weighted value from those indexes, and it is also ranked from 1 to 7, such as other European labels. Three case studies corresponding to diverse subsectors in the agro-food sector in Aragon (Spain) were tested, and one of these case studies (ready to eat meals) is presented here. Results show an index level of 5 (medium-high) for the WEUI at its present operation. Proposed improvement measures in the industry lead to a slight upgrade in the overall process of efficiency, due mainly to the water savings up to level 6 (high). An online tool for an easy calculation of the WEUI has been implemented. Up to now, 9 agro-food subsectors have been included in the tool, which is also adapted to available information in the companies. (C) 2016 Elsevier Ltd. All rights reserved.